/Engine/Source/Runtime/SlateCore/Public/Layout/WidgetPath.h
a copy of the widget path down to and including the MarkerWidget. If the MarkerWidget is not found in the path, return an invalid path.
[FWidgetPath](API\Runtime\SlateCore\Layout\FWidgetPath) GetPathDownTo ( [TSharedRef](API\Runtime\Core\Templates\TSharedRef)< const [SWidget](API\Runtime\SlateCore\Widgets\SWidget) > MarkerWidget ) const